The relatively recent advent of large scale computing networks, such as the Internet, have lead to a variety of new mechanisms for providing network-based services. One mechanism is a web service. A web service refers to software executing on one or more servers that is used specifically to provide a network-accessible interface to data, functions or other form of network resource. That is the web service uses standards-compliant interfaces to expose network resources which may be utilized by other software applications. The web service is referred to as a “web” service since it typically provides an application programming interface (API) that may be invoked by the messaging protocols executing over the hypertext transfer protocol (HTTP), which is typically associated with the “World Wide Web.” However, instead of being accessed by a user via a web browser, other software applications invoke the web service so as to make use of the functionality provided by the web services. For example, software applications may issue extensible markup language (XML)-based messages using the Simple Object Access Protocol (SOAP) using hypertext transfer protocol (HTTP) or hypertext transfer protocol secure (HTTPS) to invoke a web service.
As one example, an enterprise may utilize web services to provide access to internal systems and to allow the systems to exchange information. For example, an enterprise may deploy a web service to provide access functions to an inventory management system. Similarly, the enterprise may deploy web services to expose access to an accounting system that maintains accounts receivable information and a sales force management system that maintains customer account information. The various enterprise software systems may utilize the web services so as to directly access and exchange data with each other. In many cases, an intermediate web service may invoke one or more other web services, which may in turn utilize other web services. In this way, complex networking environments may utilize numerous web services configured to communicate with one another to exchange information, either on the same domain, or different domains.
Recently, software frameworks have been developed so as to standardize mechanisms by which web services communicate with each other and exchange data. One type of framework, referred to as a system oriented architecture (SOA) system provides an architecture for creating and using business processes packaged as interoperable web services. Utilizing the SOA framework, the independent web services exchange information via a defined enterprise services bus (ESB), which provides an abstraction layer on top of an enterprise messaging system. Moreover, the SOA system defines a context in which web services of the SOA system may be invoked. For example, services of the SOA system typically include an associated XML format file or files that web service developers may use to specify how a particular web service is invoked, e.g., available inputs and outputs, their format, and/or how to use them. An XML file that defines an interface for a web service may be referred to as a web services descriptive language (WSDL) file, where WSDL is an XML-based language that defines a model for describing the web service. Rather than defining an application programming interface for web application itself (as with a distributed or modular computing architecture as described above), an SOA system may, via a WSDL file, define the interface in terms of protocols and functionality. Additional details regarding SOA and WSDL may be found in Josuttis, N. SOA in Practice: The Art of Distributed System Design. O'Reilly. 2007, J. Farrell, H. Lausen, “Semantic Annotations for WSDL and XML Schema” W3C Recommendation, August 2007; http://www.w3.org/TR/sawsdl/, and Haas, Hugo. WSDL 2.0: What's new? XML 2004 Proceedings, each of which is hereby incorporated by reference.
Web services have become ubiquitous in nature in large-scale private and public networks due to the ease in which they may be interconnected so as to expose and utilize functionality of underlying network resources. However, the cost associated with maintaining and supporting web services by an enterprise or other entity can be significant, especially as the web services become increasingly interconnected.